Mary Adelaide Lundby (February 2, 1948 – January 17, 2009) was a state Senator from the Iowa's 18th District. She served in the Iowa Senate from 1995 to 2009, serving as Minority Leader from 2006 to 2007 and as Co-Majority Leader in 2006. She also served in the Iowa House of Representatives from 1987 to 1995, serving as Speaker pro Tempore from 1992 to 1994.